The history of medical x-ray imaging originates approximately to the time of inventing x-radiation. Concerning more advanced ways of imaging in the dental field, for example, developing of panoramic x-ray imaging was started for over a half century ago. The advancement of digital imaging especially in the 1990s has brought digital x-ray imaging apparatuses also to the dental field. The latest step of development seen in the dental field has been the generalisation of the cone beam computed tomography apparatuses designed for three-dimensional imaging of teeth and other bones of the cranial area. Among others, the computed tomography enables imaging the cranial bones and teeth as well as soft tissues. Along with many other reasons, the generalisation of odontological computed tomography imaging has been contributed, among others, by being able to get the soft tissue of the cranial area visible better in computed tomography images than e.g. in conventional transillumination images of the cranial area.
In connection with x-ray imaging of humans, one must strive for taking care of not to expose the patient to radiation more than necessary for making a diagnosis. The size of the radiation dose can be affected, among others, by choosing the best applicable imaging technique for each situation and by developing the imaging techniques themselves. A typical problem causing extra radiation load is, however, a failure in the imaging, whereby the patient has to be re-imaged. As the imaging event can last even about twenty seconds, a typical reason for failure in the imaging is that the patient moves or stirs during the imaging process.
The field of odontology commonly employs x-ray apparatuses where the patient sits or stands positioned in a patient support means during the imaging. Commonly found structures in such support means include e.g. a jaw support, a bite support, support bars positioned on the patient's temples which mainly provide point-like support sideways, and a forehead support. As examples of prior-art patient support arrangements the application publications US 2006/0227938, US 2007/0183567 and DE 3609260 can be mentioned.
For instance, in odontological panoramic and cone-beam computed tomography imagings where the imaging means rotate around the patient's head, the imaging event typically lasts of the order of 10-20 seconds. A large-size C-arm turning around the head in front of the patient's face can easily frighten the patient and, also otherwise due to the duration of the imaging event, the patient's head may tend to move from its place or turn during the exposure.
Many prior-art patient support arrangements have not necessarily been aimed at actually assisting the head staying at in place in other than one or some specific directions for the most, their use as supports for patients of different sizes can be challenging and/or they may feel uncomfortable for the patient. Discomfort can be the result of e.g. the construction of the support structure together with the materials used in it. At the same time, the material used in the support structures is often such that, although it typically absorbs x-radiation only a little and thus is no problem for the x-ray imaging of the cranial bones, its density with respect to attenuation of x-radiation can still be of such order which causes problems considering imaging of cranial soft tissues.